The file T5NoSinksBln.tif is the final truncation model.

The file T5RESIDUALSNoSinks.shp is the input residuals file used by Framework Archaeology for the creation of the final truncation model.

Treatment of the input residuals file.
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This was calculated in Surfer by subtracting the 1943 survey levels from the archaeological survey levels. The grid method in Surfer Minimum curvature with a grid density of 2m. Positive residuals were then manually removed since these could not logically exist in areas of archaeological survival (A positive residual indicates that the level at which archaeological features appear is higher than the 1943 survey level).  Visible sinks caused by levels readings taken at the base of archaeological features were manually removed. 

Positive residuals largely appear to result from areas of minimal coverage of survey points for both the T5 excavations survey data and the 1943 survey

Production of the final truncation model
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This was produced from the input file T5RESIDUALSNoSinks.shp using ArcMap 3D analyst. The methodology used Raster interpolation with the Natural Neighbours algorithm and a raster with the cell-size of 0.25 metres was produced. 

Other files
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T5ContoursNoSinks.shp was then produced from the final truncation model using ArcMap 3D analyst's contouring command.

T5 Truncation.lyr is the thematic display used in ArcMap. This typically shows the truncation using 0.25m defined intervals.